Which three factors should be taken into consideration when preparing data to be used in Contact Builder?

Contact Builder can be used to create a relational model of an organization’s data within Marketing Cloud.

Which three factors should be taken into consideration when preparing data to be used in Contact Builder? Choose 3 answer
A . Assigning data relationships and primary keys across all channels
B. Verifying data address marketing needs
C. Verifying all data extensions have a sendable value
D. Verifying each data extension has the required Email Address field populated
E. Normalizing data to reduce redundancy

Answer: A,B,C